Nina Tandon: Caring for engineered tissue

37,523 views ・ 2011-07-09

TED


Please double-click on the English subtitles below to play the video.

00:15
Good morning everybody.
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I work with really amazing,
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little, itty-bitty creatures called cells.
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And let me tell you what it's like
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to grow these cells in the lab.
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I work in a lab where we take cells out of their native environment.
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We plate them into dishes
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that we sometimes call petri dishes.
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And we feed them -- sterilely of course --
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with what we call cell culture media -- which is like their food --
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and we grow them in incubators.
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Why do I do this?
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We observe the cells in a plate,
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and they're just on the surface.
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But what we're really trying to do in my lab
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is to engineer tissues out of them.
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What does that even mean?
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Well it means growing an actual heart,
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let's say,
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or grow a piece of bone
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that can be put into the body.
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Not only that, but they can also be used for disease models.
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01:08
And for this purpose, traditional cell culture techniques
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just really aren't enough.
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The cells are kind of homesick;
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the dish doesn't feel like their home.
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And so we need to do better at copying their natural environment
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to get them to thrive.
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We call this the biomimetic paradigm --
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copying nature in the lab.
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Let's take the example of the heart,
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the topic of a lot of my research.
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What makes the heart unique?
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Well, the heart beats,
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rhythmically, tirelessly, faithfully.
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We copy this in the lab
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by outfitting cell culture systems with electrodes.
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These electrodes act like mini pacemakers
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to get the cells to contract in the lab.
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What else do we know about the heart?
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Well, heart cells are pretty greedy.
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Nature feeds the heart cells in your body
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with a very, very dense blood supply.
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In the lab, we micro-pattern channels
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in the biomaterials
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on which we grow the cells,
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and this allows us to flow the cell culture media, the cells' food,
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through the scaffolds where we're growing the cells --
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a lot like what you might expect
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from a capillary bed in the heart.
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So this brings me to lesson number one:
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life can do a lot with very little.
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02:16
Let's take the example of electrical stimulation.
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Let's see how powerful just one of these essentials can be.
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02:22
On the left, we see a tiny piece of beating heart tissue
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that I engineered from rat cells in the lab.
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It's about the size of a mini marshmallow.
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And after one week, it's beating.
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You can see it in the upper left-hand corner.
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But don't worry if you can't see it so well.
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It's amazing that these cells beat at all.
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But what's really amazing
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is that the cells, when we electrically stimulate them,
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like with a pacemaker,
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that they beat so much more.
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But that brings me to lesson number two:
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cells do all the work.
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In a sense, tissue engineers have a bit of an identity crisis here,
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because structural engineers
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build bridges and big things,
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computer engineers, computers,
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but what we are doing
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is actually building enabling technologies for the cells themselves.
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What does this mean for us?
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03:07
Let's do something really simple.
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03:09
Let's remind ourselves
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that cells are not an abstract concept.
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Let's remember that our cells sustain our lives
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in a very real way.
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"We are what we eat," could easily be described
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as, "We are what our cells eat."
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And in the case of the flora in our gut,
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these cells may not even be human.
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But it's also worth noting
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that cells also mediate our experience of life.
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Behind every sound, sight, touch, taste and smell
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is a corresponding set of cells
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that receive this information
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and interpret it for us.
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It begs the question:
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shall we expand our sense of environmental stewardship
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to include the ecosystem of our own bodies?
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03:52
I invite you to talk about this with me further,
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and in the meantime, I wish you luck.
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03:57
May none of your non-cancer cells
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become endangered species.
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04:01
Thank you.
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04:03
(Applause)
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